The candidates to become Labour leader need to "bury the format" of their "ridiculous" hustings process as they head into the final six weeks of the campaign, says Labour's former City minister, Paul Myners.

He believes the dozens of hustings in recent weeks have failed to convincingly engage candidates and audiences in a proper debate.

By the time a new leader is elected to fight the coalition, the candidates will have taken part in 56 hustings at which they are largely asked similar questions and their answers are time-limited.

Each candidate makes a two-minute statement and has 60 seconds to answer questions before being given another two minutes to summarise their views.

Myners, whose remarks chime with what many in the Labour party have been saying, told the Guardian: "I feel sorry for the candidates. I wish one of them would now say, 'enough of this – the present structure has served its purpose'. We now need to bury the format to allow single-subject discussions and to allow proper arguments to develop."

Some of the candidates are on holiday now, some have returned, but all will have resumed campaigning before the end of August, on the punishing schedule of three or four hustings a week.

On 1 September ballots will go out and although the received wisdom is that party members will vote immediately, thereby arguably making the hustings pointless, candidates are expected to keep up the breakneck pace. Myners urged them instead to overturn the party's official rules and talk more freely, ideally spending longer on particular subjects.

In particular Myners is concerned the candidates have been able to get away with paying scant regard to the economy. The peer recently caused a furore when he said in the House of Lords that he believed Labour had to persuade the public that it believed there was "nothing progressive about a deficit".

He told the Guardian it was critical the candidates use these hustings to develop their ideas about the economy and that, if they cannot show they understand that governments formed by Labour often leave office with the public books in deficit, then "its licence to govern is weakened".

Labour is sticking to shadow chancellor Alistair Darling's line that the deficit should be halved over the course of the next parliament.

Contenders for the Labour leadership have only deviated in one direction with the shadow schools secretary, Ed Balls, saying that in retrospect he believed that timeframe too swift and his supporters suggesting privately that if he won the leadership he might oppose the coalition on a platform of slowing down the wiping out of the deficit from a four- to a 10-year period.

Myners said he supported Darling and thought the policies the coalition is executing make very real the possibility of a double-dip recession, predicting "at least one quarter when GDP will go negative" by the beginning of 2011.

But while Myners mocked government charges that the opposition ran too high a level of debt, he took issue with the level of the deficit his own party left.

"I don't agree with Ed Balls. I do think the Labour party has to wrestle with the fact that it tends to leave office with large deficits. And I think its licence to govern is weakened – and it would be weakened in the future – if it could not produce credible arguments to show that it is capable of sound economic management through the cycle. We are also going to be able to make a more credible contribution to this debate if we're clearer about where we would have made cuts and where we would have made taxations."

Labour should return to an idea Myners said he accepted was discredited in execution by its own creator, Gordon Brown.

Myners said: "I am essentially arguing for the golden rule which Gordon so passionately believed in, but grew to forget, which was that: through the cycle the current government expenditure should be covered by taxation. And that borrowing should be used for investment purposes and I believe that that is a sound rule and it is an idea to adhere to, and in a world where progressive government – a government which delivers a fairer society and is fairer to and supports the needs of the vulnerable – needs to achieve its goals within the context of running a balanced budget over the cycle.

"The mistake we made as a government was that we ran large deficits in the middle part of the last decade when the economy was clearly running at full capacity.

"The maligned golden rule, which I may well be the last person to go down saying, 'please don't forget', there was some credibility to it."

He rounded on the coalition for cutting items he said he would invest in.

"How are we going to get this workforce, which is going to give us economic growth which will allow us to deliver our policy ideals, if we are cutting back on education, science and technology in schools?

"This is right to fund it with borrowing because future generations will repay the debt but also benefit from the output in productivity of those people who have been trained. That is the beauty of this model that was originally articulated by Gordon."

He also had some recommendations for what a Labour opposition should say in response to the forthcoming comprehensive spending review: "Personally I don't think anything should be ringfenced; ring-fencing makes no sense."

He says although he started off undecided between Ed and David Miliband, Ed's positions have discomfited him.

"I am classic centre-left – I come from a business background. I believe that markets are the most efficient way of allocating resources and to facilitate programmes of social and community justice.

"I have found Ed has gone more away from the position on the economy on which I am comfortable and that's why I suppose – I am not declaring – but I do find myself much more sympathetic to David Miliband.

"Ed's position on the 50p tax – I said in the Lords when we introduced the 50p tax that there would be behavioural adjustments and the yields from the tax would not be as high as expected and I think Ed has said he sees this as a tax that should be permanent – that is wrong. These people are mobile."